package demos;

import java.util.*;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentLinkedQueue;
import java.util.concurrent.CopyOnWriteArrayList;
import java.util.concurrent.CopyOnWriteArraySet;

public class Collect {
    public static void main(String[] args) {
        String s = "fhujihreq";
        StringBuffer bf = new StringBuffer();
//        StringBuilder bf = new StringBuilder();
    }

}
